Thermostatic control for grinding machines



Oct. 29, 1935. H. E. BALSIGER THERMOSTATIC CONTROL FOR GRINDING MACHINES Filed Feb. 15, 1.934 2 Sheets-Sheet 1 gawk Evro/dFBa/dz'ge Oct. 29, 1935.

H. E. BALSIGER THERMOSTATIC CONTROL FOR GRINDING MACHINES Filed Feb. 15, 1934 2 Sheets-Sheet 2 Harold C. Balm er:

Patented Oct. 29, 1935 PATENT OFFICE THERMOST'ATIC CONTROL FOR GRINDING MACHINES Harold E. Balsiger, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa., a corporation of Pennsylvania Application February 15, 1934, Serial No. 711,433

6 Claims.

This invention relates to carriage control mechanism and particularly for means for controlling the feed of a grinding wheel carriage toward the work.

An object of the invention is to provide means for maintaining a uniform feed of the carriage through any ranges of temperature variations'and particularly to provide means responsive to temperature changes in the fluid in the feed control system for controlling the feed. The control 'is particularly adapted for use on a grinding machine such as that shown in my copendin'g application Serial No. 623,225, filed July 18, I932 'for Feed controls.

Referring to the accompanying drawings, which are made a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a vertical section through the f-eed control reservoir showing the feed control valves,

Figure 2 is a view inelevation of the said reservoir and valves showing a solenoid for operating one of the valves.

Figure 3 is a sectional plan view on line 3-3 of Figure 1.

Figure 4 is a diagrammatic end elevation of a grinding machine showing the wheel feed mechanism with which my device is used.

In the drawings numeral I9 indicates a fluid reservoir from which a fluid such as oil may flow freely through a port 22, a valve 26, a port 25, a chamber 24 .and a pipe 2| to a feed control cylinder 38. A wheel feed cylinder 40 is controlled by valve 4|. The ball valve 26 is positioned to permit fluid to flow freely from the reservoir but prevents its return to the reservoir. Valve ports 21 and 28 provide for return of fluid from the Wheel feed cylinder through chamber 23 into reservoir I9- The port 21 is controlled by a needle valve 29 which is manually operable through a valve stem35. The port 28 is controlled by a needle valve having a valve stem 30 to which is attached an operating arm 3|. The arm 3| is connected by a spring link 32 with the armature 33 of a solenoid 34 so that the valve stem 30 may be electrically operated .and, as shown in the copending application referred to, may be operated at a predetermined point to partially close off the port 28 to slow down movement of the wheel carriage or other carriage upon which the control device is mounted. A spring 31 operates in opposition to the movement of the solenoid to restore the valve to a predetermined open position. The valves, solenoid and associated elements may be mounted on a suitable support 36.

The present invention provides means for adjusting the opening at valve port 28 in response to variations in temperature of the fluid within the control system. This heat responsive device consists of ,a valve I01 adapted to vary the opening of port 28. This valve is slidably mounted withina bore in the end of the valve stem A bar m9 is secured to the end of the valve stem 30. This bar is provided with slots ill in each and Bars IIB are pivotally secured to the bar H39 by pins 'I I3 which pass through the slots I I I. Bushings I I5 which are slightly longer than the width of the bar H0 permit said bars to be secured to bar Hi9 without effecting the pivotal action. The bars I iii are also pivotally attached by means of pin II4 to the valve Ill'l. A spring I08 is mounted within the bore in stem 36 adapted to urge the I valve it? outward of this bore against the bars Hi). The bars H0 and the bar its are made of material having different co-efficients of expansion so that for a given change of temperature in the bars there will be a greater expansion or contraction in the bars I In than in bar I69. This difference will be reflected in valve I01 by lengthwise movement.

The purpose of this is that a rise in temperature of the oil in the feed control system will cause a corresponding change of temperature in the bars I09 and III) which will in turn move the valve IO'I to change the opening of port 28.

As the oil or other fluid in the control system gradually becomes warmer its resistance of flow through the valve opening of port 28 becomes less and less and in order that there will be a uniform flow of oil through this port during the feeding time of the machine the opening will have to be closed gradually at such .a rate as to compensate for the decreasing resistance of the flow of the oil.

It can be seen that the bars I I0 and W9 acting on the valve I01 move the valve to accomplish this end.

The means to adjust the bars I I0 in slots I I I on bar I09 makes possible by changing the angular relation between the two bars I I0 to increase or decrease the rate of lengthwise movement of the valve I01 as the temperature changes. The greater the angle the greater the movement of valve ml per each degree of temperature change and vice versa.

It is therefore apparent that by the use of this adjustment the device can be adjusted to compensate for temperature changes for different grades of liquids that may be used in the control system, and is therefore not limited to any peculiarity of any one particular fluid.

A cover plate 39 is removably secured to the 7 side of the casing housing the valve I91 to provide access to the valve to inspect or to adjust the bars H0.

While the thermostat control has been shown as applied to the automatically operated valve stem 38 it might be used on manually operated valve 29 instead.

While a particular form of heat sensitive device has been shown obviously other methods of conrolling the valve iii! in response to temperature changes could be used and such modifications are held to be within the purview of this invention.

It will be obv ous to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown in the drawings and described in the specification, but only as indicated by the appended claims. 7

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a feed control device, a fluid reservoir having a fluid conduit connected thereto, a check valve for permitting fluid to flowi'reely out of said reservoir into said conduit, a plurality of needle valves for controlling the flow of fluid from said conduit into said reservoir, manually operable means for adjusting one of said needle valves and heat responsive means for adjusting the other of said needle valves.

2. In a feed control device of the kind described, a reservoir having a fluid conduit connected thereto, a valve for permitting fluid to flow freely from said reservoir to said conduit, a plurality of ports for controlling the flow of fluid from said conduit to said reservoir, 2. manually operable needle valve in control of one of said ports, an automatically operable needle valve in control of the other of said ports and heat responsive means on said last-named valve for further controlling the port in response to changes in temperature of the fluid within said reservoir.

3. In a feed control device of the kind described, a reservoir having a fluid conduit connected thereto, a check valve for permitting fluid to flow freely from said reservoir to said conduit, a plurality of ports for controlling the flow of fluid from said conduit to said reservoir, a manually adjustable needle valve in control of one of said ports, an automatically operable needle valve in control of another of said ports, and heat responsive means for adjusting one of said needle valves.

4. In a machine of the kind described, a work support, a wheel support, fluid means to provide a relative transverse movement of said supports, means to eflect movement at high speed, means to change said high speed to a grinding speed including a fluid controlled feed regulator and heat sensitive means adapted to maintain said grinding feed uniform regardless of variation in temperature of said fluid in said regulator.

5. In a grinding machine, a carriage, a fluid motor for moving said carriage, a hydraulic regulator for controlling the rate of movement of said carriage, a valve for controlling said hydraulic regulator and heat responsive means for adlusting said valve.

6. In a machine of the kind described a pair of carriages, fluid means to provide a relative feeding movement of one of said carriages toward the other, fluid mechanism to control said feeding movement, including a valve, and heat sensitive means controlling said valve, whereby to maintain a constant rate of flow of fluid therethru regardless of variation in temperature of the fluid.

HAROLD E. BALSIGER. 

